The present invention relates to a method of manufacturing a liquid crystal display element and, more particularly, to a liquid crystal injection method for a ferroelectric liquid crystal display element.
It is expected that ferroelectric liquid crystal display elements are put into practical applications such as a large-capacity display or a high-speed liquid crystal shutter for a printer since it has a memory property and a high-speed response property on the order of micro-second. When ferroelectric liquid crystal display elements are put into practical applications, they pose a technical problem of an alignment property of a liquid crystal.
The aligning methods for a ferroelectric liquid crystal which are presently used can be largely classified into a method of rubbing an organic thin film, and a method of obliquely vapor-depositing an inorganic material such as a metal oxide. In the aligning method utilizing a rubbing treatment, since a large number of linear alignment defects caused by a difference in layer structure appear in a rubbing axis direction and a direction almost perpendicular to the axis direction, a contrast ratio of black and white levels is considerably decreased, and it is hard to impart a memory property as the major characteristic feature of the ferroelectric liquid crystal to an aligned liquid crystal.
In contrast to this, with the method utilizing oblique vapor deposition, an aligning film which includes little alignment defects can be obtained. When an opposite gradient alignment structure is employed wherein SiO oblique vapor deposition films having opposite inclination directions are formed on opposing surfaces of a pair of substrates, as described in a method disclosed in Japanese Pat. Laid-Open No. 62-192742, a liquid crystal display element having a memory property and a high contrast ratio can be obtained.
However, a ferroelectric liquid crystal display element using SiO oblique vapor deposition alignment films formed by opposite gradient alignment suffers from local misalignment when a liquid crystal display element becomes large in size (e.g., a 10.times.10 (cm) display element, a 25 (cm).times.1 (cm) elongated liquid crystal shutter element, and the like). As a result, uniform alignment cannot be attained.